That may be the origin but it's definately not the connotation.Quote from rew:
Actually "niggardly" has no etymological connection to "nigger", the latter being a corruption of the Spanish word for "black" and the former being of Scandinavian origin. But Americans are far more politically correct than literate, so are easily alarmed and horrified by one man calling another a miser.
http://en.wikipedia.org/wiki/Controversies_about_the_word_"niggardly"